Is that it's in hexadecimal. So that's the first stage - convert it into decimal. I assume. After that...?

42

Apparently a simple Google search will solve it for you. (It's an ad for "spy recruitment", or so they say...)

I gather it's some sort of software program that, once decoded, gives you directions to part 2 of the test. Given the message in the 'success' page, it looks like they're recruiting cybercrime analysts

http://www.canyoucrackit.co.uk/soyoudidit.asp

They say that Helsinki is pretty in the spring.
They say that Helsinki is pretty in the spring.
They say that Helsinki is pretty in the spring.
19 25 11 53 44
19 25 11 53 44
19 25 11 53 44
19 25 11 53 44
23 23 57 16 57
23 23 57 16 57
23 23 57 16 57
23 23 57 16 57
13 11 65 42 42
13 11 65 42 42
13 11 65 42 42
13 11 65 42 42
They say that Helsinki is pretty in the spring.
They say that Helsinki is pretty in the spring.
They say that Helsinki is pretty in the spring.
They say that Helsinki is pretty in the spring.
sssssssssssssssssssssssssssssssssssssssssssssssss shhhhhhhhhhhhhhhh
ssssssssssssssssssssssssssssss crackle crackle screeeeeeeeee ssssssssssssssssssssssss screeeeeee crackle screeeeeee sssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss
sssssssssssssssssssssssssssssssssssssssssssssssss shhhhhhhhhhhhhhhh
ssssssssssssssssssssssssssssss crackle crackle screeeeeeeeee ssssssssssssssssssssssss screeeeeee crackle screeeeeee sssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss
sssssssssssssssssssssssssssssssssssssssssssssssss shhhhhhhhhhhhhhhh
ssssssssssssssssssssssssssssss crackle crackle screeeeeeeeee ssssssssssssssssssssssss screeeeeee crackle screeeeeee sssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss
sssssssssssssssssssssssssssssssssssssssssssssssss shhhhhhhhhhhhhhhh
ssssssssssssssssssssssssssssss crackle crackle screeeeeeeeee ssssssssssssssssssssssss screeeeeee crackle screeeeeee sssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss

the answer is

"Gents toilets, Kings Cross Station, behind third cistern on the left"

.

I can't tell you any more about the job because I signed the Official Secrets Act. And it was 35 years ago.

..."Bollocks"

it is indeed part of a test for potential recruits at MI5 and part of an ad for a job going for 24k, in a recent news story ex-GCHQ members said if you're clever enough to crack this you can get work with private security firms that pay three times as much as the government which is why they have such a high staff turnover.

According to this - http://www.theregister.co.uk/2011/12/06/hidden_gchq_code_breaking_challe... - the chances are that unless you're really into crypto and advanced techniques/IT, you'll be in trouble right away.